Effect of grouting quality on flexural behavior of corroded post-tensioned concrete T-beams

The durability of post-tensioned concrete (PTC) bridge structures has been greatly threatened by the corrosion of steel strands, especially in the case of insufficient grouting. In this paper, the effect of grouting quality on flexural behavior of corroded post-tensioned concrete (CPTC) beams is experimentally investigated with two groups of T-beams, i.e., five fully grouted beams in Group A and five partially grouted beams in Group B. Results indicate that when the mass loss of steel strands in Group A ranges from 0 % to 10.47 %, the cracking load decreases by 5.8821.57 %, and the ultimate bearing capacity decreases by 5.45–30.45 %. While for Group B, when the mass loss of steel strands ranges from 0 % to 14.26 %, the cracking load decreases by 3.75–25.00 %, and the ultimate bearing capacity decreases by 7.41–44.91 %. It is observed that as the degree of corrosion increases, both cracking load and ultimate bearing capacity of the beam gradually deteriorate, with the flexural capacity of partially grouted beams deteriorating faster. Built on this and with the model of bond reduction coefficient, an analytical method is proposed to predict the flexural capacity of CPTC beams under different grouting conditions. The developed method provides good predictions compared with experimental results of current study and from literature, paving the way for accurate assessment of the flexural bearing capacity of PTC beams with different grouting qualities in corrosive environments.